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// SPDX-License-Identifier: GPL-2.0-only
/*
* NAND driver for the MikroTik RouterBoard 4xx series
*
* Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
* Copyright (C) 2015 Bert Vermeulen <bert@biot.com>
* Copyright (C) 2020 Christopher Hill <ch6574@gmail.com>
*
* This file was based on the driver for Linux 2.6.22 published by
* MikroTik for their RouterBoard 4xx series devices.
*
* N.B. driver probe reports "DMA mask not set" warnings which are
* an artifact of using a platform_driver as an MFD device child.
* See conversation here https://lkml.org/lkml/2020/4/28/675
*/
#include <linux/platform_device.h>
#include <linux/mtd/rawnand.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/version.h>
#include <mfd/rb4xx-cpld.h>
struct rb4xx_nand {
struct rb4xx_cpld *cpld;
struct device *dev;
struct nand_chip chip;
struct gpio_desc *ale;
struct gpio_desc *cle;
struct gpio_desc *nce;
struct gpio_desc *rdy;
};
static int rb4xx_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 8;
oobregion->length = 3;
return 0;
case 1:
oobregion->offset = 13;
oobregion->length = 3;
return 0;
default:
return -ERANGE;
}
}
static int rb4xx_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 0;
oobregion->length = 4;
return 0;
case 1:
oobregion->offset = 4;
oobregion->length = 1;
return 0;
case 2:
oobregion->offset = 6;
oobregion->length = 2;
return 0;
case 3:
oobregion->offset = 11;
oobregion->length = 2;
return 0;
default:
return -ERANGE;
}
}
static const struct mtd_ooblayout_ops rb4xx_nand_ecclayout_ops = {
.ecc = rb4xx_ooblayout_ecc,
.free = rb4xx_ooblayout_free,
};
static u8 rb4xx_nand_read_byte(struct nand_chip *chip)
{
struct rb4xx_nand *nand = chip->priv;
struct rb4xx_cpld *cpld = nand->cpld;
u8 data;
int ret;
ret = cpld->read_nand(cpld, &data, 1);
if (unlikely(ret))
return 0xff;
return data;
}
static void rb4xx_nand_write_buf(struct nand_chip *chip, const u8 *buf, int len)
{
struct rb4xx_nand *nand = chip->priv;
struct rb4xx_cpld *cpld = nand->cpld;
cpld->write_nand(cpld, buf, len);
}
static void rb4xx_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
{
struct rb4xx_nand *nand = chip->priv;
struct rb4xx_cpld *cpld = nand->cpld;
cpld->read_nand(cpld, buf, len);
}
static void rb4xx_nand_cmd_ctrl(struct nand_chip *chip, int dat,
unsigned int ctrl)
{
struct rb4xx_nand *nand = chip->priv;
struct rb4xx_cpld *cpld = nand->cpld;
u8 data = dat;
if (ctrl & NAND_CTRL_CHANGE) {
gpiod_set_value_cansleep(nand->cle, !!(ctrl & NAND_CLE));
gpiod_set_value_cansleep(nand->ale, !!(ctrl & NAND_ALE));
gpiod_set_value_cansleep(nand->nce, !(ctrl & NAND_NCE));
}
if (dat != NAND_CMD_NONE)
cpld->write_nand(cpld, &data, 1);
}
static int rb4xx_nand_dev_ready(struct nand_chip *chip)
{
struct rb4xx_nand *nand = chip->priv;
return gpiod_get_value_cansleep(nand->rdy);
}
static int rb4xx_nand_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device *parent = dev->parent;
struct rb4xx_nand *nand;
struct mtd_info *mtd;
int ret;
if (!parent)
return -ENODEV;
nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
if (!nand)
return -ENOMEM;
platform_set_drvdata(pdev, nand);
nand->cpld = dev_get_drvdata(parent);
nand->dev = dev;
nand->ale = devm_gpiod_get_index(dev, NULL, 0, GPIOD_OUT_LOW);
if (IS_ERR(nand->ale))
dev_err(dev, "missing gpio ALE: %ld\n", PTR_ERR(nand->ale));
nand->cle = devm_gpiod_get_index(dev, NULL, 1, GPIOD_OUT_LOW);
if (IS_ERR(nand->cle))
dev_err(dev, "missing gpio CLE: %ld\n", PTR_ERR(nand->cle));
nand->nce = devm_gpiod_get_index(dev, NULL, 2, GPIOD_OUT_LOW);
if (IS_ERR(nand->nce))
dev_err(dev, "missing gpio nCE: %ld\n", PTR_ERR(nand->nce));
nand->rdy = devm_gpiod_get_index(dev, NULL, 3, GPIOD_IN);
if (IS_ERR(nand->rdy))
dev_err(dev, "missing gpio RDY: %ld\n", PTR_ERR(nand->rdy));
if (IS_ERR(nand->ale) || IS_ERR(nand->cle) ||
IS_ERR(nand->nce) || IS_ERR(nand->rdy))
return -ENOENT;
gpiod_set_consumer_name(nand->ale, "mikrotik:nand:ALE");
gpiod_set_consumer_name(nand->cle, "mikrotik:nand:CLE");
gpiod_set_consumer_name(nand->nce, "mikrotik:nand:nCE");
gpiod_set_consumer_name(nand->rdy, "mikrotik:nand:RDY");
mtd = nand_to_mtd(&nand->chip);
mtd->priv = nand;
mtd->owner = THIS_MODULE;
mtd->dev.parent = dev;
mtd_set_of_node(mtd, dev->of_node);
if (mtd->writesize == 512)
mtd_set_ooblayout(mtd, &rb4xx_nand_ecclayout_ops);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0)
nand->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
nand->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
#else
nand->chip.ecc.mode = NAND_ECC_SOFT;
nand->chip.ecc.algo = NAND_ECC_HAMMING;
#endif
nand->chip.options = NAND_NO_SUBPAGE_WRITE;
nand->chip.priv = nand;
nand->chip.legacy.read_byte = rb4xx_nand_read_byte;
nand->chip.legacy.write_buf = rb4xx_nand_write_buf;
nand->chip.legacy.read_buf = rb4xx_nand_read_buf;
nand->chip.legacy.cmd_ctrl = rb4xx_nand_cmd_ctrl;
nand->chip.legacy.dev_ready = rb4xx_nand_dev_ready;
nand->chip.legacy.chip_delay = 25;
ret = nand_scan(&nand->chip, 1);
if (ret)
return -ENXIO;
ret = mtd_device_register(mtd, NULL, 0);
if (ret) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,8,0)
mtd_device_unregister(nand_to_mtd(&nand->chip));
nand_cleanup(&nand->chip);
#else
nand_release(&nand->chip);
#endif
return ret;
}
return 0;
}
static int rb4xx_nand_remove(struct platform_device *pdev)
{
struct rb4xx_nand *nand = platform_get_drvdata(pdev);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,8,0)
mtd_device_unregister(nand_to_mtd(&nand->chip));
nand_cleanup(&nand->chip);
#else
nand_release(&nand->chip);
#endif
return 0;
}
static const struct platform_device_id rb4xx_nand_id_table[] = {
{ "mikrotik,rb4xx-nand", },
{ },
};
MODULE_DEVICE_TABLE(platform, rb4xx_nand_id_table);
static struct platform_driver rb4xx_nand_driver = {
.probe = rb4xx_nand_probe,
.remove = rb4xx_nand_remove,
.id_table = rb4xx_nand_id_table,
.driver = {
.name = "rb4xx-nand",
},
};
module_platform_driver(rb4xx_nand_driver);
MODULE_DESCRIPTION("Mikrotik RB4xx NAND driver");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
MODULE_AUTHOR("Christopher Hill <ch6574@gmail.com");
MODULE_LICENSE("GPL v2");
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